Geometric distribution case edit
If X is a random variable and has Geometric distribution (the parameter is p, and the number of event is k),
![{\displaystyle \operatorname {E} [X]=\sum _{k=1}^{\infty }kp(1-p)^{k-1}={\frac {1}{p}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/c0f96958b17c7f9f48f7d2c39d84b9b8e05813a4)
because it can be derived from the equation below.
 | This user is a student editor in Cornell_University/Probability,_Statistics,_and_Data_Analysis_for_the_Physical_Sciences_(Fall_2021). |
- ^ A modern introduction to probability and statistics : understanding why and how. Michel Dekking. London: Springer. 2005. ISBN 978-1-85233-896-1. OCLC 262680588.
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